Two highly sensitive and efficient salamo-like copper(II) complex probes for recognition of CN

Two salamo-like copper(II) complex probes, L¹-Cu²⁺ and L²-Cu²⁺, were designed and synthesized for sensitive and efficient identification of CN^-. UV spectroscopy, high resolution mass spectrometry, RGB analysis and naked eye recognition were performed to explore their recognition mechanisms. High resolution mass spectra indicated that the probes L¹-Cu²⁺ and L²-Cu²⁺ formed complexes with CN^-. The two probes could recognize CN^- by the naked eye and the color of the solution changed from light yellow to red. In terms of application, the contents of CN^- in the environmental water samples were tested. In addition, the optimal pH ranges for probe detection of CN^- were investigated by pH value measurement.